The purpose of this multidisciplinary Center is to explore the neural bases of language and cognitive development in children, combining cognitive/behavioral methods with structural brain imaging (quantitative MRI analyses and diffusion tensor imaging) and event-related brain potentials (ERP), to study normal and abnormal brain development, and the alternative forms of brain organization that can emerge under pathological conditions. Our extensive body of behavioral work, coupled with advances in neuro-imaging methods, has positioned us to begin the investigation of a new set of critical issues that are the basis for the proposed research: 1) specific sensory, perceptual and attentional underpinnings of the observed deficits;2) relationships between primary deficits and impairment of higher cognitive functions such as language and social communication;and 3) the emerging structural organization of the neural systems that support these functions. The populations to be studied are children with: typical development (TD);Specific Language Impairment (LI);Early Unilateral Focal Brain Lesions (FL);High Functioning Autism (HFA);and Williams Syndrome (WS). Project 1 will examine sensory and perceptual processing using EEG/ ERPs to determine whether specific and differential profiles exist between typically developing children and our clinical populations, how they map onto respective neural structures, and how these profiles relate to higher cognitive functions. Project 2 will examine the integrity of attention and working memory (WM) in children with neuro-developmental disorders;alterations in brain spatial structure associated with differences in these domains;and the relationship of spatial attention and WM function to both early sensory processing and more complex levels of cognition. Project 3 will examine affect and social communication, and will utilize neuro-imaging studies to correlate brain structural differences with competence in these areas. Project 4 will examine higher level language and literacy skills in the context of early sensory processing capacities, attention/WM, and social communication, as well as correlate outcomes from volumetric analyses of specific brain regions with language and literacy abilities. Core A will provide the Center infrastructure, administrative organization, subject identification/recruitment, database functions, and statistical support. Core B will provide baseline screening, experimental testing, and subject tracking. Core C will conduct MRI scanning for all subjects, and provide the Projects with quantified measures of specific cortical/subcortical structures and white matter tracts. The state of the art imaging techniques proposed in Core C will allow us to obtain an excellent overview of the neuroanatomical features in the clinical populations to be studied. The "value-added" factor of integrating cognitive studies with structural imaging and ERP analyses in a closely interrelated set of studies is enormous, and allows for maximum efficiency in use of time and funds. The clinical relevance of the studies proposed is also very significant;findings from the proposed studies may lead to earlier diagnosis and intervention for specific cognitive deficits, and interventions that are more directly targeted to the underlying sensory, perceptual or cognitive deficit rather than to the final common denominator (e.g., language impairment).